////////////////////////////////////////////////////////////////////////
//
// Copyright (C) 2011-2021 The Octave Project Developers
//
// See the file COPYRIGHT.md in the top-level directory of this
// distribution or <https://octave.org/copyright/>.
//
// This file is part of Octave.
//
// Octave is free software: you can redistribute it and/or modify it
// under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Octave is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Octave; see the file COPYING.  If not, see
// <https://www.gnu.org/licenses/>.
//
////////////////////////////////////////////////////////////////////////

#if defined (HAVE_CONFIG_H)
#  include "config.h"
#endif

#include <QDesktopWidget>
#include <QFile>
#include <QIcon>
#include <QLayout>
#include <QTextBrowser>
#include <QTextStream>
#include <QThread>

#include "release-notes.h"
#include "gui-preferences-nr.h"
#include "news-reader.h"
#include "octave-qobject.h"

#include "defaults.h"

namespace octave
{
  release_notes::release_notes (void)
    : QWidget (nullptr), m_browser (nullptr),
      m_release_notes_icon (":/actions/icons/logo.png")
  {
#if 0
    // The following code was in main-window.cc.  How should that be
    // handled here?
    if (dw_icon_set_names[icon_set_found].name != "NONE")
      m_release_notes_icon = dw_icon_set_names[icon_set_found].path
        + "ReleaseWidget.png";
    else
      m_release_notes_icon = ":/actions/icons/logo.png";
#endif

    std::string news_file = config::oct_etc_dir () + "/NEWS";

    QString news;

    QFile *file = new QFile (QString::fromStdString (news_file));
    if (file->open (QFile::ReadOnly))
      {
        QTextStream *stream = new QTextStream (file);
        news = stream->readAll ();
        if (! news.isEmpty ())
          {
            // Convert '<', '>' which would be interpreted as HTML
            news.replace ("<", "&lt;");
            news.replace (">", "&gt;");
            // Add HTML tags for pre-formatted text
            news.prepend ("<pre>");
            news.append ("</pre>");
          }
        else
          news = (tr ("The release notes file '%1' is empty.")
                  . arg (QString::fromStdString (news_file)));
      }
    else
      news = (tr ("The release notes file '%1' cannot be read.")
              . arg (QString::fromStdString (news_file)));


    m_browser = new QTextBrowser (this);
    m_browser->setText (news);

    QVBoxLayout *vlayout = new QVBoxLayout;
    vlayout->addWidget (m_browser);

    setLayout (vlayout);
    setWindowTitle (tr ("Octave Release Notes"));

    m_browser->document ()->adjustSize ();

    int win_x, win_y;
    get_screen_geometry (win_x, win_y);

    resize (win_x*2/5, win_y*2/3);
    move (20, 20);  // move to the top left corner
  }

  void release_notes::display (void)
  {
    if (! isVisible ())
      show ();
    else if (isMinimized ())
      showNormal ();

    setWindowIcon (QIcon (m_release_notes_icon));

    raise ();
    activateWindow ();
  }

  // FIXME: This function is duplicated in main_window.cc.  Maybe it
  // should be a utility function?

  void release_notes::get_screen_geometry (int& width, int& height)
  {
    QRect screen_geometry = QApplication::desktop ()->availableGeometry (this);

    width = screen_geometry.width ();
    height = screen_geometry.height ();
  }
}
